Messages in this thread | | | Date | Mon, 6 May 2013 12:01:15 -0700 | From | Tejun Heo <> | Subject | Re: [PATCH 2/2] lockdep: check that no locks held at freeze time |
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On Fri, May 03, 2013 at 02:04:10PM -0700, Colin Cross wrote: > From: Mandeep Singh Baines <msb@chromium.org> > > We shouldn't try_to_freeze if locks are held. Holding a lock can cause a > deadlock if the lock is later acquired in the suspend or hibernate path > (e.g. by dpm). Holding a lock can also cause a deadlock in the case of > cgroup_freezer if a lock is held inside a frozen cgroup that is later > acquired by a process outside that group. > > History: > This patch was originally applied as 6aa9707099c and reverted in > dbf520a9d7d4 because NFS was freezing with locks held. It was > deemed better to keep the bad freeze point in NFS to allow laptops > to suspend consistently. The previous patch in this series converts > NFS to call _unsafe versions of the freezable helpers so that > lockdep doesn't complain about them until a more correct fix > can be applied.
I don't care about %current change, especially given that it's a debug interface but that really should be a separate patch, so please split it out if you want it (and I think we want it).
Thanks.
-- tejun
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